From lignocellulosic biomass to levulinic acid: A review on acid-catalyzed hydrolysis

This study focused on optimization of reaction conditions for formation of sugars and levulinic acid from marine algal biomass Gelidium amansii using acid catalyst and by using statistical approach. By this approach, optimal conditions for production of sugars and levulinic acid were found as follows: glucose (reaction temperature of 139.4 degrees C, reaction time of 15.0 min, and catalyst concentration of 3.0%), galactose (108.2 degrees C, 45.0 min, and 3.0%), and levulinic acid (160.0 degrees C, 43.1 min, and 3.0%). While trying to optimize the conditions for the production of glucose and galactose, levulinic acid production was found to be minimum. Similarly, the production of glucose and galactose were found to be minimum while optimizing the conditions for the production of levulinic acid. In addition, optimized production of glucose required a higher reaction temperature and shorter reaction time than that of galactose. Levulinic acid was formed at a high reaction temperature, long reaction time, and high catalyst concentration. The combined results of this study may provide useful information to develop more economical and efficient systems for production of sugars and chemicals from marine biomass.

Feasibility of saccharide-rich invasive seaweed biomass valorisation for levulinic acid and syngas production.

OPEFB is a waste product from oil palm mills and is abundant in quantity. OPEFB is a lignocellulosic compound containing cellulose, hemicellulose, and lignin. The cellulose in OPEFB can be converted into levulinic acid, while hemicellulose can be converted into furfural. The consumption of furfural and levulinic acid in Indonesia is increasing, and so far, the demand has been met through imports. Pretreatment is the first stage in converting OPEFB into valuable products. In this paper, we have simulated furfural and levulinic acid production from OPEFB using two pretreatment methods: ammonia soaking and ammonia expansion. Both process simulations were carried out using Superpro Designer v9.0, with 17,520 metric tons OPEFB/year capacity as input raw material. The simulation of furfural and levulinic acid production using the ammonia expansion pretreatment process resulted in feasibility indicators including a payback period of 2.56 years, an ROI (Return on Investment) of 34.07%, and an IRR (Internal Rate of Return) of 28.62%. On the other hand, using the ammonia-soaking process resulted in an IRR of 22.26%. These parameters indicate that furfural and levulinic acid production is more economically viable using the ammonia expansion pretreatment process than the ammonia soaking pretreatment process.

Modeling of sugarcane bagasse conversion to levulinic acid using response surface methodology (RSM), artificial neural networks (ANN), and fuzzy inference system (FIS): A comparative evaluation

Levulinic acid (LA) is a platform compound regarded as a promising organic intermediate for the synthesis of various chemicals such as fuel additives, plasticizers, solvents, and pharmaceuticals. Traditionally, LA is produced via acid-catalyzed dehydration and hydrolysis of lignocellulosic biomass, but this process involves challenges such as high temperatures and pressures, the use of strong acids, byproducts formation, and limitations in recovery and purification. To provide an alternative for chemical synthesis, we previously designed an integrated process to produce LA from glucose using genetically engineered Pseudomonas putida KT2440. However, as the consumption of the produced LA could not be completely prevented, its overall yield was limited. Therefore, in this study we constructed P. putida strains with additional knock-out of the lva operon genes (lvaAB, lvaE, and lvaR) in a pcaIJ knock-out strain, and introduced the aroG, asbF, and adc genes to design an LA production pathway. The pcaIJ, lvaR double knock-out strain P. putida HP205 produced 20.42mM of LA from glycerol, and culture condition including temperature, glucose concentration, and nitrogen source were optimized. Under optimal conditions, P. putida HP205 produced 73.9mM (8.58g/L) LA in fed-batch fermentation. When crude glycerol was used as the substrate, both LA production and cell growth were enhanced. This study presents the impact of the LA transcriptional regulator and demonstrates a strategy for enhanced LA production in P. putida.

Production of levulinic acid from corn cob residue in a fed-batch acid hydrolysis process

This study employed a statistical methodology to investigate the optimization of conversion conditions and evaluate the reciprocal interaction of reaction factors related to the process of red-algae Gracilaria verrucosa conversion to sugars (glucose, galactose), levulinic acid and 5-hydroxymethylfurfural (5-HMF) by acidic hydrolysis. Overall, the conditions optimized for glucose formation included a higher catalyst concentration than did those for galactose, and these conditions for galactose were similar to those for 5-HMF. Levulinic acid production, meanwhile, was optimized at a higher reaction temperature, a higher catalyst concentration, and a longer reaction time than was glucose, galactose or 5-HMF production. By this approach, the optimal yields (and reaction conditions) for glucose, galactose, levulinic acid, and 5-HMF were as follows: glucose 5.29 g/L (8.46 wt%) (reaction temperature 160 °C, catalyst concentration 1.92%, reaction time 20 min), galactose 18.38 g/L (29.4 wt%) (160 °C, 1.03%, 20 min), levulinic acid 14.65 g/L (18.64 wt%) (180.9 °C, 2.85%, 50 min), and 5-HMF 3.74 g/L (5.98 wt%) (160.5 °C, 1%, 20 min).

Empty fruit bunch (EFB) generated as waste in plantation mill activities in Malaysia is a potential biomass feedstock of biorefinery for fuels and chemicals production. Levulinic acid and succinic acid, two out of 12 chemical building blocks identified by Department of Energy (DOE) to be used in synthesis of high-value materials, can be produced from biochemical conversion of the EFB. This paper evaluates sustainability assessment of EFB to levulinic acid and succinic acid. The assessments include net present value (NPV), global warming potential (GWP), and Hazard identification and ranking (HIRA) to cater for economic, environment, and safety performances, respectively. The results show that the levulinic acid production is more economically attractive than succinic acid production. The environmental impact quantification reveals that the levulinic acid has lower GWP score of 6.3 kgCO2-eq/kg levulinic acid than succinic acid with 11.2 kgCO2-eq/kg succinic acid. Meanwhile, the succinic acid production is inherently safer than levulinic acid production due to its less severe operating conditions.

The production of levulinic acid and formic acid from red macroalga Kappaphycus alvarezii using methanesulfonic acid

Design and techno–economic analysis of levulinic acid production process from biomass by using co-product formic acid as a catalyst with minimal waste generation

The projections of ionic liquids as green solvents in chemical processes have increased in recent years. Ionic liquid is a versatile chemical with various applications. The aim of this review is to present a comprehensive perspective of ionic liquid for processing carbohydrate biomass by considering the recent progress in this field. Special attention is given to the application of ionic liquids for the production of 5-hydroxymethyl furfural (5-HMF) and levulinic acid (LA). Factors affecting the catalytic conversion of carbohydrate biomass in ionic liquid and the mechanisms of 5-HMF and LA production are also presented. In addition, the recyclability of the ionic liquid for carbohydrate biomass processing is discussed. The viewpoint for the application of functionalized ionic liquid as potential green solvent and catalyst is also highlighted. Future studies pertinent to carbohydrate biomass conversion in ionic liquids to 5-HMF and LA could use this review for selecting the appropriate reaction conditions required to achieve their specific goals. Besides, combination of technologies from ionic liquids and biomass processing strategies for the production of various fuels and value-added chemicals can be comprehended for applications in a lignocellulosic biorefinery.

Biomass-derived levulinic acid (LA) and its esters are currently envisaged as versatile, renewable platform chemicals. In this study, cellulosic pulp derived from the cooking of lignocellulosic biomass with active oxygen and solid alkali was employed as raw material for the formation of LA or ethyl levulinate (EL). This pretreatment process is highly effective for the delignification and deconstruction of lignocellulose matrix, making a facile degradation of the resulting cellulosic pulp to LA or EL. At this point, the acid-catalyzed hydrolysis or ethanolysis of cellulosic pulp was optimized by response surface methodology (RSM), offering desirable LA yield of 65.3% or EL yield of 62.7%, which is significantly higher than those obtained from raw biomass. More importantly, coking behavior on the inwall of the reactor was eliminated during the hydrolysis or ethanolysis of cellulosic pulp, which is one of the top challenges for the acid-catalyzed conversion of biomass in an industrial scale.

5-(Hydroxymethyl)furfural (HMF) and levulinic acid production from glucose in a cascade of reactions using a Lewis acid (CrCl3) catalyst together with a Brønsted acid (HCl) catalyst in aqueous media is investigated. It is shown that CrCl3 is an active Lewis acid catalyst in glucose isomerization to fructose, and the combined Lewis and Brønsted acid catalysts perform the isomerization and dehydration/rehydration reactions. A CrCl3 speciation model in conjunction with kinetics results indicates that the hydrolyzed Cr(III) complex [Cr(H2O)5OH](2+) is the most active Cr species in glucose isomerization and probably acts as a Lewis acid-Brønsted base bifunctional site. Extended X-ray absorption fine structure spectroscopy and Car-Parrinello molecular dynamics simulations indicate a strong interaction between the Cr cation and the glucose molecule whereby some water molecules are displaced from the first coordination sphere of Cr by the glucose to enable ring-opening and isomerization of glucose. Additionally, complex interactions between the two catalysts are revealed: Brønsted acidity retards aldose-to-ketose isomerization by decreasing the equilibrium concentration of [Cr(H2O)5OH](2+). In contrast, Lewis acidity increases the overall rate of consumption of fructose and HMF compared to Brønsted acid catalysis by promoting side reactions. Even in the absence of HCl, hydrolysis of Cr(III) decreases the solution pH, and this intrinsic Brønsted acidity drives the dehydration and rehydration reactions. Yields of 46% levulinic acid in a single phase and 59% HMF in a biphasic system have been achieved at moderate temperatures by combining CrCl3 and HCl.

Biorefineries–Industrial Processes and Products: Status Quo and Future Directions

Optimisation of glucose and levulinic acid production from the cellulose fraction of giant reed (Arundo donax L.) performed in the presence of ferric chloride under microwave heating